Controlling pollution caused by hydrocarbon compounds, for example crude oil pollution, in soils and waters by bioremediation is acquiring increasing significance. Major advantages are afforded by the inexpensive in situ processes where no space is required for waste disposal. Microorganisms which consume hydrocarbon compounds are valuable tools in the context of this technology, even under comparatively unfavorable basic conditions, providing their enrichment and/or their growth at the point of pollution can be sufficiently stimulated. From the more recent literature, reference is made to the articles in Chemische Industrie 5/91, 10 to 12 "Hunger for Crude Oil" and in Erdol und Kohle-Erdgas, 44, April 1991, 197 to 200, Th. Hopner et al. "Die Olkatastrophe im Persisch-Arabischen Golf (The Oil Catastrophe in the Persian/Arabian Gulf)" and the extensive literature cited therein.
The working principle of bioremediation is based on optimal promotion of the growth of the pollution-consuming microorganism populations. Two important aids are of paramount significance in this regard: firstly, the supply of growth-promoting elements which are generally not available in sufficient concentrations in the polluted area. These growth-promoting elements are primarily inorganic and/or organic compounds of nitrogen and phosphorus which are made available as nutrient concentrates for stimulation and as growth aids for the accelerated growth of the microorganisms consuming hydrocarbon compounds. Secondly, preformed concentrates of suitable hydrocarbon-consuming microorganisms are frequently used, in particular to accelerate biological degradation in the initial phases, and may be applied to the polluted areas, for example at weekly intervals. However, depending on the particular situation, more particularly the previous individual history of the polluted areas to be treated, it may even be assumed that the use of microorganism concentrates is not necessary. In general, this will always be the case when the natural process of biological degradation has already resulted in the development of sufficient concentrations of microorganism strains, cf. in this connection for example the 2nd of the literature references cited at the beginning.
Hitherto unpublished German patent application DE-P 41 31 714.9 proposes an improved nutrient mixture for the bioremediation of polluted soils and waters. The mixture described in this document is in the form of a storable solution or emulsion and contains P- and N-sources in a liquid mixed phase of biocompatible water-soluble carrier components based on glycerol and biocompatible oil-soluble carrier components based on glycerol esters. Although the application in question proposes a solution in which only substances which are readily biodegradable are introduced into the contaminated soil sample, another C-source is introduced on a significant scale in the form of the glycerol esters. Under unfavorable growth conditions, the presence of these components can promote the growth of microorganisms which are unsuitable for degrading pollutants so that they proliferate to the detriment of the degrading microorganisms.